Perez had a 2.06 ERA in 39 games during the first half last year, and his ERA went up to 4.18 in 29 games over the second half.
In September, his ERA ballooned all the way up to 10.29.
"I guess at the end I felt tired, but that's why I took the offseason off," Perez said. "I didn't play winter ball because I'm not 21 anymore, so I have to take care of myself. I rested until December. I feel good right now, and maybe shorter would be better this year. I'll be ready every time like always."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.